Can set shadowResolution to 0 but not 1.

So I have a button that changes QualitySettings.shadowResolution to low when clicked. I use this code. QualitySettings.shadowResolution = 0 And it does as expected, it changes the shadow res to “low” when clicked. However, when I try to set it to something higher via QualitySettings.shadowResolution = 1 or QualitySettings.shadowResolution = 2 I get the following error: error CS0266: Cannot implicitly convert type 'int' to 'UnityEngine.ShadowResolution'. An explicit conversion exists (are you missing a cast?) Which doesn’t make much sense to me. Any help would be greatly appreciated.

QualitySettings.shadowResolution = ShadowResolution.Low;
QualitySettings.shadowResolution = ShadowResolution.Medium;
QualitySettings.shadowResolution = ShadowResolution.High;
QualitySettings.shadowResolution = ShadowResolution.VeryHigh;